This page, from Ray Kurzweil’s The Age of Spiritual Machines, follows Moore’s law of exponential growth of computer power. Kurzweil believes that a revolutionary change (”singularity”) will take place as the machine-brain surpasses the human brain.
Note that although computers will exceed human-brain capacity early in the 21st century, this may not mean much, since most humans spend almost no time thinking comprehensively about the future, nor do computers. Facebook and pornography are the major uses. Edward R. Murrow said that “Television will be the most revolutionary educational tool of the 20th century.” Look what happened. On the other hand, fairly primitive computers, handled intelligently, were producing astounding ideas as early as the 1970’s—The Limits to Growth, Mankind at the Turning Point, Reshaping International Order, MOIRA, etc.